Anthocyanin, also known as anthocyan, is a flavonoid compound, and has the following physiological activities: i) increasing flexibility of capillaries, thus improving the swellability and retractility of blood vessels and preventing angiorrhexis; ii) eliminating free radicals which may result in blood vessel sclerosis, thus preventing angiosclerosis; and iii) strengthening capillaries in eyes and other organs, and preventing pathological changes of these organs. Anthocyanins have been used in foods and medicines. Those used in foods typically have been anthocyanidins such as pelargonidin, cyanidin, delphinidin, peonidin, petunidin, malvidin, or anthocyanins formed by these anthocyanidins binding with glucose, galactose or arabinose respectively. Anthocyanins are mostly monosaccharides and diglycosides.
A proanthocyanin is a condensed tannin from a plant source, which produces anthocyanins when heated in an acidic medium. Proanthocyanins can reduce the levels of cholesterol and low-density lipoprotein, thus prevent thrombosis and cardio-cerebro-vascular disease, and protect DNA from damage of free radicals, thus preventing genetic mutations that may cause cancer.
Resveratrol and its glucoside are active polyphenol substances, and are abundantly contained in the Chinese medicine known as Polygonurn cuspidaturn. Apart from its strong antioxidant function, resveratrol can inhibit three major stages (induction, initiation and development) of cytometaplasia and tissue mutation in the process of cancer development. It has been reported that resveratrol can delay the aging process by protecting DNA from chemical damage. In addition, experiments with regard to the life-increasing mechanism of resveratrol revealed that resveratrol can increase life span by about 70% by activating Sir2 enzymatic expression. Hence, resveratrol can influence health by activating the Sir2 enzyme in different levels and paths.